From: Jeff King <p...@peff.net>
Receive-pack feeds its input to either index-pack or
unpack-objects, which will happily accept as many bytes as
a sender is willing to provide. Let's allow an arbitrary
cutoff point where we will stop writing bytes to disk.
Cleaning up what has already been written to disk is a
related problem that is not addressed by this patch.
The problem is that git-gc can clean up tmp_pack_* files
after their grace time expired, but that may not be
enough if someone tries to "git push" in a loop.
A simple fix is to call register_tempfile() in
open_pack_file(), and just have index-pack clean up the
file on its way out.
But there are harder cases. For instance, if somebody
pushes a 500MB file, and there is a pre-receive hook that
says "too big; I won't accept this". And then they push in
a loop, the incoming pack has already been accepted into
the repository by the time the pre-receive hook runs.
It's not possible to just delete it, because we don't know
if other simultaneous processes have started to depend on
the objects.
Signed-off-by: Jeff King <p...@peff.net>
Signed-off-by: Christian Couder <chrisc...@tuxfamily.org>
---
Documentation/config.txt | 5 +++++
Documentation/git-receive-pack.txt | 3 +++
builtin/receive-pack.c | 12 +++++++++++
t/t5546-push-limits.sh | 42 ++++++++++++++++++++++++++++++++++++++
4 files changed, 62 insertions(+)
create mode 100755 t/t5546-push-limits.sh
diff --git a/Documentation/config.txt b/Documentation/config.txt
index 0bcb679..f5b6061 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -2517,6 +2517,11 @@ receive.unpackLimit::
especially on slow filesystems. If not set, the value of
`transfer.unpackLimit` is used instead.
+receive.maxsize::
+ If the size of a pack file is larger than this limit, then
+ git-receive-pack will error out, instead of accepting the pack
+ file. If not set or set to 0, then the size is unlimited.
+
receive.denyDeletes::
If set to true, git-receive-pack will deny a ref update that deletes
the ref. Use this to prevent such a ref deletion via a push.
diff --git a/Documentation/git-receive-pack.txt
b/Documentation/git-receive-pack.txt
index 000ee8d..0ccd5fb 100644
--- a/Documentation/git-receive-pack.txt
+++ b/Documentation/git-receive-pack.txt
@@ -33,6 +33,9 @@ post-update hooks found in the Documentation/howto directory.
option, which tells it if updates to a ref should be denied if they
are not fast-forwards.
+A number of other receive.* config options are available to tweak
+its behavior, see linkgit:git-config[1].
+
OPTIONS
-------
<directory>::
diff --git a/builtin/receive-pack.c b/builtin/receive-pack.c
index 92e1213..8c2943d 100644
--- a/builtin/receive-pack.c
+++ b/builtin/receive-pack.c
@@ -46,6 +46,7 @@ static int transfer_unpack_limit = -1;
static int advertise_atomic_push = 1;
static int advertise_push_options;
static int unpack_limit = 100;
+static off_t max_input_size;
static int report_status;
static int use_sideband;
static int use_atomic;
@@ -212,6 +213,11 @@ static int receive_pack_config(const char *var, const char
*value, void *cb)
return 0;
}
+ if (strcmp(var, "receive.maxsize") == 0) {
+ max_input_size = git_config_int64(var, value);
+ return 0;
+ }
+
return git_default_config(var, value, cb);
}
@@ -1650,6 +1656,9 @@ static const char *unpack(int err_fd, struct shallow_info
*si)
if (fsck_objects)
argv_array_pushf(&child.args, "--strict%s",
fsck_msg_types.buf);
+ if (max_input_size)
+ argv_array_pushf(&child.args,
"--max-input-size=%"PRIuMAX,
+ (uintmax_t)max_input_size);
child.no_stdout = 1;
child.err = err_fd;
child.git_cmd = 1;
@@ -1678,6 +1687,9 @@ static const char *unpack(int err_fd, struct shallow_info
*si)
fsck_msg_types.buf);
if (!reject_thin)
argv_array_push(&child.args, "--fix-thin");
+ if (max_input_size)
+ argv_array_pushf(&child.args,
"--max-input-size=%"PRIuMAX,
+ (uintmax_t)max_input_size);
child.out = -1;
child.err = err_fd;
child.git_cmd = 1;
diff --git a/t/t5546-push-limits.sh b/t/t5546-push-limits.sh
new file mode 100755
index 0000000..b38d508
--- /dev/null
+++ b/t/t5546-push-limits.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+
+test_description='check input limits for pushing'
+. ./test-lib.sh
+
+test_expect_success 'create remote repository' '
+ git init --bare dest
+'
+
+# Let's run tests with different unpack limits: 1 and 10
+# When the limit is 1, `git receive-pack` will call `git index-pack`.
+# When the limit is 10, `git receive-pack` will call `git unpack-objects`.
+
+while read unpacklimit filesize filename
+do
+
+ test_expect_success "create known-size ($filesize bytes) commit
'$filename'" '
+ test-genrandom foo "$filesize" >"$filename" &&
+ git add "$filename" &&
+ test_commit "$filename"
+ '
+
+ test_expect_success "set unpacklimit to $unpacklimit" '
+ git --git-dir=dest config receive.unpacklimit "$unpacklimit"
+ '
+
+ test_expect_success 'setting receive.maxsize to 512 rejects push' '
+ git --git-dir=dest config receive.maxsize 512 &&
+ test_must_fail git push dest HEAD
+ '
+
+ test_expect_success 'bumping limit to 4k allows push' '
+ git --git-dir=dest config receive.maxsize 4k &&
+ git push dest HEAD
+ '
+
+done <<\EOF
+1 1024 one-k-file
+10 2048 two-k-file
+EOF
+
+test_done
--
2.10.0.rc0.3.g8535b4c
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